How can I infinitely loop a png sequnce in blender?
Name the images so that they have sequential numbers at the end of the name of the file.

Enable the images as planes addon.

In the add menu select add images as planes. Select the image sequence you want to import. 



Click on the cogwheel icon on the right of the import menu to expand the options and select "Animate Image Sequence", set the material to Shadeless, Check Alpha and set it to Premultiplied. Enable Auto Refresh.


A plane with the image mapped to it will appear.

To make the image sequence loop endlessly enable Cyclic on the material.